Racial and Ethnic Differences in Rural-Urban Trends in 5-Year Survival of Patients With Lung, Prostate, Breast, and Colorectal Cancers: 1975-2011 Surveillance, Epidemiology, and End Results (SEER)
Authors: Marquita W. Lewis-Thames, Marvin E. Langston, Saira Khan, Yunan Han, Lindsay Fuzzell, Shuai Xu, Justin Xavier Moore
Journal: JAMA Network Open (2022)

<h3>Importance</h3> Considering reported rural-urban cancer incidence and mortality trends, rural-urban cancer survival trends are important for providing a comprehensive description of cancer burden. Furthermore, little is known about rural-urban differences in survival trends by racial and ethnic groups. <h3>Objective</h3> To examine national rural-urban trends in 5-year cancer-specific survival probabilities for lung, prostate, breast, and colorectal cancers in a diverse sample of racial and ethnic groups. <h3>Design, Setting, and Participants</h3> This cross-sectional study used an epidemiologic assessment with 1975 to 2016 Surveillance, Epidemiology, and End Results (SEER) data to analyze patients diagnosed no later than 2011. Patients were classified as living in rural and urban counties based on the 2013 Rural-Urban Continuum Codes. <h3>Main Outcomes and Measures</h3> The 5-year cancer-specific survival probability of urban and rural patients for each cancer type was estimated by fitting Cox proportional hazard regression models accounting for race, ethnicity, tumor characteristics, and other sociodemographic characteristics. A generalized linear regression model was used to estimate the mean estimated probability of survival for each stratum. Joinpoint regression analysis estimated periods of significant change in survival. <h3>Results</h3> In this study, data from 3 659 417 patients with cancer (median [IQR] age, 67 [58-76]; 1 918 609 [52.4%] male; 237 815 [6.5%] Hispanic patients; 396 790 [10.8%] Black patients; 2 825 037 [77.2%] White patients) were analyzed, including 888 338 patients with lung cancer (24.3%), 750 704 patients with colorectal cancer (20.5%), 987 826 patients with breast cancer (27.0%), and 1 023 549 patients with prostate cancer (28.0%). There were 430 353 rural patients (11.8%). Overall, there was an equal representation of rural and urban men. Rural patients were likely to be non-Hispanic White individuals, have more cases of distant tumors, and be older. Rural and non-Hispanic Black patients for all cancer types often had shorter survival. From 1975 to 2016, the 5-year lung cancer survival rate was shorter for non-Hispanic Black rural patients in 1975 at 48%, while increasing to 57% for both non-Hispanic Black urban and rural patients in 2011, but still the shortest among all cancer types. In 1975, the longest survival rate was observed in urban Asian and Pacific Islander patients with breast cancer at 86%, and in 2011, the longest survival rate was observed in urban non-Hispanic White patients at 92%. <h3>Conclusions and Relevance</h3> Even after accounting for sociodemographic and tumor characteristics, these findings suggest that non-Hispanic Black patients with cancer are particularly vulnerable to cancer burden, and resources are urgently needed to reverse decades-old survival trends.